Lost all calendar events on iPhone after iOS 18.5 update

It appears it’s deleted mine too, although initially I didn’t put the two together, but I’ve done the update recently (automatically) went to check my calendar today and notice past events are missing.

I’ve tried a few things after reading some guides on here, but alas it hasn’t worked.

I’ve tried searching to see if just not showing but still on iCloud but isn’t finding anything

Me too!!! At first I thought my daughter somehow cleared everything but it appears this has happened to lots of people and recently. I just noticed mine within the last week. All events gone. I’ve done all the troubleshooting and contacted Apple. I have a callback with them tomorrow morning so hopefully I get help. Soooo freaking annoyed. 😑

I had the same issue after updating to IOS 18.5. Whether it’s actually this update, or the deprecation of iTunes (which I always successfully used to sync my Outlook calendars to iPhone/iPad) isn’t entirely clear. Apple have been nothing short of hopeless in “supporting” people.

Here’s what I think has happened to me, and forgive me as I’m no expert. So, I downloaded iCloud for windows. It told me I would sync (“sync” being the important part) my outlook calendars with iCloud, as well as my contacts. The contacts were synced, but the Outlook calendars were wiped clean. 16 years of diaries gone in an instant. Unfortunately, my backup from Outlook calendars were backed up to Windows One Drive. So, when iCloud wiped the calendars, the .pst file for the backup on One Drive was automatically updated to wipe that too.

Unfortunately, I didn’t have a stand-alone backup of the .pst file done recently, and had to revert to the last one I had for December 2024. I’ve managed to rebuild some of my diaries, but it’s a nightmare. I haven’t had the guts to try it again. If the so-called support from Apple senior team so far is anything to go by, it doesn’t inspire confidence. But there surely must be a way to synchronise data between devices and platforms that doesn’t risk losing valuable information we all depend on.

I’m going to reach out to Apple again tomorrow to see if they’ll walk me through an idiot-proof sync, but I’m not holding my breath waiting for success. One thing’s for sure, I’ll have several backups of the .pst file on several stand-alone drives before I do anything!

Any other ideas or comments welcomed.

Thank you SO much for this! It worked perfectly and all of my calendar entries are back! Life saver! Thank you!